Differential drive clutch for automobiles



Jul 1 1924. 1,499,336 J.BLACKBURN DIFFERENTIALDRIVE CLUTCH FOR AUTOMOBILES Filed Jan. 12, 1920 3 Sheets-Sheet 1 4% a E 4 25 5 A? 20 fXa J.BLACKBURN DIFFERENTIAL- DR IVE CLUTCH FOR AUTOMOB ILES Filed Jan, 12'. 1920 3 Sheets-Sheet 2 Lwmw July 1', 1924.

, J. BLACKBURN DIFFERENTIAL DRIVE CLIUTCH FOR AUTOMOBILES File d Jan. 12, 1920 s Sheets-Sheet 5 Patented July 1, 1924.

oNiTEo STATES JASPER BLACKBURN, OF WEBSTER GROVES, MISSOURI.

. DIFFERENTIAL DRIVE CLUTCH FORIAUTOMOBILES.

Application filed January 12, 1920. Serial No. 350,783.

T all whom it may concern:

Be it known that I, JASPER BLACKBURN,

a citizen of the United States of America,

and resident of \Vebster Groves, in the county of St. Louis and State of Missouri,

have invented certain new a-nd useful Im provements in Differential Drlve Clutches for Automobiles, of which the following isa specification containing a full, clear, and exact description, reference being had to the accompanying drawings, forming part thereof. I W I This invention relates toimprovements in differential drive clutches for automobiles, and has for its primary object a driving mechanism which is attached to each of the rear wheels thereby doing away with the differential gear made use of in the present type of drives. i 1

A further object is to construct a differential clutch for automobiles which is'attached "directly to the wheels and within the, brake drum, and is so arranged that one of the wheels may travel faster than the other, as

frequently occurs especially inrounding a corner, p g

In the construction of my device,

Fig. 1 is a sectional viewshowin-gthe main driveshaft and my improvements attached to one of, the'wheels; f 1' Fig. 2 an enlarged view of one of the wheels with my device in position Fig.3 a view of the positive drivendisc; Fig. t a view of the idle or looselymonnted driving disc; 7 I .i i

Figs. 5 and 6 are views showing therecesses in which the roller pawls controlled by the discs of Figs. 3 and 4 grip for driving the car forward and backwardy Fig. 7 is a side view of one of the roller pawls, and a I I Fig. 8 a view of. the other roller pawl :made use of.

Fig. 9-is a vertioalsectional view of on of the discs showing the spring actuated means for forcing wardly.

Fig. 10

the. roller pawls outis a side elevation of the loose disc.

I Fig. 11 is an enlarged viewo f one side of the differential, showing the forward drive.

recesses 42 formed in the inner peripherles,

. Fig. 12 is a similar view, showing the rear.- ward drive. I k v I In the construction of-my device, 15 rep resents the propeller shaft of an automobile, to the end of which is attached a bevel gear The purpose of this hook willfbe subseroller 39 which is likewise chamfered.

"ward and backward drive.

16 which meshes with the bevel gear 17. This bevel gear 17 is provided with elongated hubs 18, these hubs having a central rectangulareopening, as indicated by the numeral 19. "Within this opening the rectangular .ends 20 of the axle 21 are inserted, each of the rectangular ends being provided with a depression 22, these serving as a seat forthe set screw 23. My object in forming these recesses in the axle 21 is to prevent its withdrawal or shiftingtbackward and forward after the set screw has. beensecured. I may, however, use.a pin which is driven entirely through the hub 18 and through the axle, but in any event it is de- 'sirable to have the end of the shaft formed rectangular so as to take awaythe shearing tendency. I

The opposite vided with alrectangular portion 2% and a reducedcylindrioal portion 25. Over the rectangular portion 24 is placed a disc 26,

"thisdisc being provided with arecess 27.

end of the axle 21 e ic-,

This recess is socshaped as to form a hook 28.;

quently explained in detail.

. Over the cyl'ndri'cal OIlZlOIl of the shaft is placed a disc 29 in which isformed and hook is adapted to register with the recured to the disc 29 fits. a

In the vrecesses 27 and 30 the. roller pawl 36 is placed, this roller awl being provided with a reduced portion 37, and has both of its ends chamfered, as indicated bythe numeral 38. j I a This chamferingis intended to reduce the riding surface of the roller and reduce friction. Within the recess 32 is placedthe As will be seen from the drawings, the

roller pawl 36 is made ofsuflicient length to extend throughboth of the discs 26 and 29, while the roller 39 extends only through the disc 26. Surrounding the discs29 and 26 arerings 4O andtl, these rings having the recesses in one'ring extending in an optlie other ring, so asto take care of .the for- These rings 40 a similar recess 30 and hook 31; This recess I posit'e direction to the recesses. formed in and 41 are mounted within the brake drum '43 of an automobile, and are secured thereto by means of bolts 44. V

The nut 45 secures the wheel and the driving mechanism to the axle 21. This being a common construction,-it will not be described in detail.

If desired, I may place a spring actuated shoe, as indicated by the numeral 46, back 10 of each roller pawl so as to have a positive outward movement against each one of the pawls. p The operation of my device is as follows: After the engine has been started, and

transmission thrown in, the axle 21 is caused In the forward movementthis to revolve. w 7

revolution will be in the directlon of the arrow, shown in Fig. 11.

reduced portion 37 of the roller 36. This will'have a tendency to forcethe roller outward, and at the same time, interlock the discs '26 and'29. The two discs are now car- 25 ried in the direction indicated by the arrow in Fig. .11, which rotation causes the roller 36 to move outward on the inclined faces 46 of these discs. This outward movement will 7 continue until the enlarged portion of the roller 36 enters oneof the recesses 42 in the ring 41. "These recesses limit the outward movement of the roller 36,a11d prevent the disc 29 from-turningany further and normally holds the roller in the recess and 3 against accidental dislodg ment.- The reduced portion 37 resting against the'inclined face 46 of the disc 26, receives'the torque frQ Il' the axle 21, when the carvis started forward. In the event that one of the wheels .40 rolls faster than the other, the-roller pawl 'on that wheel is carried forward in its recess, faster than the discs revolve, which permlts 1t. to enter the recesses formed -11'1 sa1d d scs, thus.disengagmgthat wheel from the driving axle, and allowing it to travel at a greater rateof speed, while the remaining wheel still receives power from the axle. "In reversing the car, the discs are driven in "the direction'indicated by the arrow in Fig.

50 '12. The disc 26 commences to'revolve first,

allowing the hook 28 to grip the reduced portion of the roller pawl, whichfhas atendency' to force the roller. forward, and remove. it from the recess 42. Q At this. period,

the shoulder 48 contacts with the-shoulder 47, placing both discs in operation. This movement .notalonedraws out the roller 36 completely from the recesses 42, but also .seats fit in the'recesses 3O and'27. When this is donethe continued rotation 'of the discs forces the roller39 'to'ride outward 'on the inolinedfface 49,; untilit isseated on one of the recesses 42, after which the" wheels are driven 'by the-axle. The same compensation 5 for moving gone wheelvfaster is'allo-wed in This movement will first rotate the disc 26, and cause the 20 cam or inclined face 46to contact with the the rearward drive, but in the rearward drive the projection 35 takes the place of the reduced portion 37 of the roller 36 to lock thetwo discs together. This locking of the discs is necessary, since where no provision is made for locking the disks in the rearward drive, the disc 29 would have a tend ency to twist the roller 36, and cause it to jam in the recesses formed in the discs 26 and 29, and thereby prevent the roller'36 from becoming readily forced outward when the forward drive is used. As before stated, the reduced portion 37 of the roller 36, is for the purpose of binding the two discs together in the forward drive, and still allow a certain amount of lost movement to the disc 26, which is essential so that one roller can be' disengaged from its driving position before the other one commences to come'into action.

Havin fully described .Iny invention, what I cIaim is V 1. In a. differential drive for automobiles wherein an axle is provided, 'and'wheels loosely mounted on theax'le-and adapted to revolve freely thereon, a clutch member the loose disc, forlimit-ing the amount of V rotation o'f'the fixed disc in relation thereto. 2. In a differential drive for automobiles which employs anaxle and atraction'w'heel loosely mounted ateach end thereof, a clutch mechanism comprising a ring shaped housing secured to a wheel,'sa'id ring shaped housing having recesses formed on the inner periphery thereof and extending partially'the width of the housing andvin oppositedirections, a pair of discs located 7 within the housing, one of which is rigidly secured to the axle, theother loosely mounted thereon, aprojection formed on the loosely mounted disc and adapted to enter a recess formed on the rigid disc,-un-

dercut recesses formed in the periphery of each of said discs, roller pawls mounted 'in said recesses, said roller'pawls adapted to engage the recessesformed in the housing for causing'the wheel to rotate 'when driving ina forward or. rearward direction, said roller apawls and recesses-being so arranged as to allow the wheel to travel faster than the speed of the. axle.

'3. In a differential drive for automobiles in which an axle having wheelsrotatably mounted on each end is employed, a'clutch mechanism comprising a housing secured to a wheel, a disc loosely mounted on the shaft within the housing and adjacent the wheel, a disc rigidly secured to the axle and mounted adjacent the first mentioned disc and within the housing, roller pawls carried by said discs and adapted to engage with recesses formed in the housing when the axle is revolved in either direction, said roller pawls adapted to be disengaged from the housing by the partial rotation of the fixed disc in relation to the loose disc, means located on the loose disc for limiting the amount of rotation of the fixed disc in relation thereto, and means carried by the discs for withdrawing one of the roller pawls and projecting the other outward when the movement of the axle is reversed.

l. In a differential drive for motor vehicles employing an axle capable of being driven and wheels mounted on each end of said axle, which wheels are free to rotate, a clutch mechanism comprising a ring shaped housing secured toa wheel, recesses "formed on the inner periphery of said housing and extending partially the width of the housing and in opposite, directions, a pair of discs located within the housing, one of said discs being rigidly secured to the axle, the other loosely mounted thereon and located between the rigid disc and the wheel, a projection formed on the loosely mounted disc and adapted to enter a recess formed in the rigidly mounted disc, said discs provided on their periphery with undercut recesses, roller pawls mounted in I said recesses, said roller pawls adapted to be forced out and connect the recesses formed in the housing for driving the vehicle in a forward or rearward direction, said roller pawls' and recesses being so arranged asto allow the wheel to travel faster than the speed of the axle, and meanscarried by the discs for withdrawing one of the roller pawls when the movement of the axle is reversed.

name to this specification. I

JASPER BLACKBURN, 

